Spark plug assembly



United States Patent G 3,012,085 SPARK PLUG ASSEMBLY Harold D. Regar,Temple, Pa. (P.0. Box 495, Woodside Ave, Alsace Manor, Reading, Pa.)Filed Feb. 13, 1959, Ser. No. 793,095 1 Claim. (Cl. 123-169) Thisinvention relates to improvements in internal combustion engines, and itmore particularly relates to improvements in spark plug assemblies.

One of the problems which has heretofore never been adequately solved isthat relating to proper combustion control and more particularly thatrelating to the relief of high torque combustion or what is known asdetonation. Another problem is that relating to spark plug timing forobtaining a greater amount of fuel economy and smoother runningconditions both when idling and at all other speeds.

It is one object of the present invention to overcome the above andother difficulties by providing a means for slowing down the burningrate of compressed gases without loss of power or improper heat controlof the spark plug.

Another object of the present invention is to provide a means to cushionengine combustion in general at all speeds including the idling speed.

Another object of the present invention is to provide a means forgreatly increasing fuel economy in internal combustion engines.

Another object of the present invention is to prevent spark plug foulingcaused by piston oil pumping and to maintain the plugs clean burning andfree from carbon deposits regardless of the severity of the oil pumpingcondition.

Other objects of the present invention are to provide an improved sparkplug assembly, of the character described, that is easily andeconomically produced, which is sturdy in construction, and which ishighly efiicient in operation.

With the above and related objects in view, this invention consists inthe details of construction and combina tion of parts, as will be morefully understood from the following description, when read inconjunction with the accompanying drawing in which:

FIG. 1 is a side elevational view of a spark plug assembly embodying thepresent invention.

FIG. 2 is a partly sectional and partly elevational view taken generallyon the line 2-2 of FIG. 1.

FIG. 3 is a cross-sectional view taken on line 33 of FIG. 2.

Referring in greater detail to the drawing wherein similar referencecharacters refer to similar parts, there is shown a spark plug assembly,generally designated 10, which comprises a spark plug 12, of the usualstandard construction, and a pre-ignition chamber 14.

The spark plug 12 is provided with a threaded stem or extension 16 onwhich is mounted the usual electrodes 18, these electrodes 18 being atthe lower end thereof.

The threaded stem 16 is engaged in a threaded bore 20 of the chamber 14.This bore 20 connects, at its lower end, directly with a tapered passage22. The passage 22 is provided with its wider end at the top, this widerend forming an uninterrupted and continuous extension of bore 20 with noshoulders in between so that a smooth, continuous flow passage isprovided. The narrower, bottom end of tapered passage 22 is alsocontinuously extended into a straight vertical passage 24 with theelimination of any shoulders or other obstructions therebetween. Thelower end of passage 24 is open and is defined by a gradually, outwardlycurved inner lip 26. v

The upper part of chamber 14 is heXagonally-shaped on its outer surface,as at 28, to permit the use of an appro- 3,012,035 Patented Dec. 5, 1961priate wrench or similar tool, while at its lower end, the chamber v14is reduced to form a nipple portion 30 having external threads anddefining the lower straight passage 24.

The nipple portion 30 is separated from the upper portion of the chamber14 by an external shoulder 32, and bearing on this shoulder 32 is acopper ring 34 surrounding the upper end of nipple portion 30.

Although the chamber 14 is threadcdly engaged on the stem 16 of thespark plug, it is spaced from the upper portion of the spark plug by asufiicient distance to accommodate a ring 36 of copper or copper alloy.This ring 36 is integral with an outwardly-inclined plate 38 of the samemetal. The ring 36 is releasably clamped between the chamber 14 and theupper portion of the spark plug 12.

The nipple 30 is connected to the standard cylinder head of an internalcombustion engine with the copper ring 34 engaged against the cylinderhead. Since the standard cylinder head is cooled by a cooling fluid suchas air or water, this cooling effect is transferred through theconductive copper ring 34 to the p re-ignition chamber 14 whereby thechamber 14 is maintained externally at approximately the sametemperature as the cooled cylinder head. At the same time, the gasmixture which is pre-ignited in passage 22 and expands therein, flowsdown through the restricted passage 24 and then gradually expands atoutwardly tapered lip 26 before it flows into the main combustionchamber of the engine cylinder. However, since there are no shoulders,bafiies or other obstructions to the flow between passage 22 and themain combustion chamber, there is a minimum of turbulence and thereforea minimum of heat generation on the walls of the chamber 14.

The combined eifects of the heat dissipation of the copper ring 34 andthe diminution of turbulence within the chamber 14 results incomparatively cool operating conditions. In addition, for completenormal running temperature in a dry burning engine (when there is no oilpumping), the ring 36 is clamped between the spark plug 12 and thechamber 14 (as illustrated in the drawing). This ring, carrying theplate 38, aids heat dissipation since the plate 38 acts as an air-cooledfin.

If the engine is pumping oil, then the ring 36 may be removed and a ringsuch as ring 34 may be substituted. This substituted ring will then actas a heat conductor, thereby increasing the temperature at the area ofthe spark plug electrodes. This increased temperature will burn offcarbon deposits keeping the spark plug electrodes clean. If the oilpumping is very severe, then the ring 36 is re placed by a conventionalcopper type collapsible spark plug gasket (not shown) since this willcause closer contact between the spark plug 12 and chamber 14. Thisgives even less cooling but the resultant hotter temperatures enable thespark plug electrodes to be more effectively burned clean. Nevertheless,even though such hotter temperatures are effected around the spark plugelectrodes, the total heat absorption in the chamber '14 is effectivelyreduced because of the smooth flow conditions therein and because of theheat dissipation effects of ring 34.

Because of the slower burning conditions existing in the chamber 14, thespark timing can readily be advanced resulting in added fuel economywith standard gasoline. This is due to the fact that slow burningeliminates pings ing or detonation, (thereby providing smoother engineperformance because the pressure stroke of the piston is sustained. Incontrast, faster burning systems have detonation or flash burning atpiston dead center point which tends to shorten pressure time. As aresult, the engine operates roughly and inefi'iciently. To amelioratesuch 3 conditions, the timing must be retarded in such engines, therebyresulting in low mileage or fuel inefiiciency.

Although this invention has been described in considerable detail, suchdescription is intended as being illustrative rather than limiting,since the invention may be variously embodied, and the scope of theinvention is to be determined as claimed.

Having thus set forth and disclosed the nature of this invention, whatis claimed is:

A spark plug assembly comprising a spark plug having an externallythreaded stem provided with electrodes at the lower end thereof, apre-ignition chamber having an internally threaded bore, said spark plugstembeing threadedly engaged in said bore, a continuous, smooth,uninterrupted frusto-conical tapered passage extending continuously fromone end of said threaded bore, the taper angle of said tapered passageto its axis being substantially 20, the wider end of said taperedpassage being connected to said threaded bore, the diameter of saidwider end being no greater than that of said threaded bore, a straightcylindrical passage of the same width as the narrower end of saidtapered passage and continuously connected to said narrower end, theaxial length of said tapered passage being at least equal to the axiallength of said straight cylindrical passage, the diameter of saidstraight cylindrical passage being at least half that of said wide endof said tapered passage, a gradu- 5 ally widening internal lip at thefree end of said straight passage which is opposite the end connected tosaid tapered passage, and a spark plug stem thread externally on saidstraight passage to releasably connect to a threaded spark plug apertureof an engine cylinder head of an 10 internal combustion engine.

References Cited in the file of this patent UNITED STATES PATENTS1,357,661 Vail Nov. 2, 1920 15 1,392,364 Smith Oct. 4, 1921 1,495,215Williams May 27, 1924 1,750,063 Sorg Mar. 11, 1930 2,236,762 Ottofy Apr.1, 1941 2,238,852 Regar Apr. 15, 1941 20 2,702,537 Wright et al Feb. 22,1955 FOREIGN PATENTS 216,391 Great Britain May 29, 1924

